Ice Circle ... how does it form ?

Yesterday I took this photo of an ice circle in the middle of frozen Linlithgow Loch.

Can anyone explain how it has been formed ?

[atsimg]http://files.abovetopsecret.com/images/member/ed5cd336349b.jpg[/atsimg]

Full picture can be seen here Ice Circle

[edit on 25-12-2009 by bigyin]

Nice catch!

Apparently some are caused by methane emissions whilst others seem to occur with slow moving water in colder climates.


Google - Ice Circles

Hope this helps.

There is no movement in this water. Gas could be a reason.

What you appear to have is known as an ice circle. What actually happens is that partially frozen water or water with large ice slabs, in slow moving water, is sheared off at curves in the water body, causing an eddy to form (or whirpool in some cases). The movement of the ice in the eddy, grinds against other ice in the area, and the edges a sheared off leaving a perfectly formed circle.

Its quite a rare phenomena so you were very lucky to get the picture, especially one so vast

That looks great. It must have been quite a sigh


If someone would care to explain this :

Another variation. It's moving...

Thanks for your post.

Actually i can understand how the moving ones form. It is caused by the current of the moving water underneath the ice.

However the one I saw is on still water. There is no current. I cant think what would cause it to form.

reply to post by bigyin


I read some more about this. I think i do understand the difference now, besides the interesting facs other have postet. So you're found could be the "ice pan", as you say no current

Anyways that pic is awesome...

Ice circles occur at bends in the river where the accelerating water creates a force called 'rotational shear', which breaks off a chunk of ice and twists it around. As the disc rotates, it grinds against surrounding ice — smoothing into a perfect circle.[3]

Another kind of ice circle are actually ice pans, or surface slabs of ice that form in the center of a lake or creek, instead of along the water's edge. They can be explained by quick shifts in temperature. As water cools, it releases heat that turns the water into frazil ice — a collection of loose, needle-shaped ice particles that can cluster together in an ice pan. If a lake accumulates enough frazil ice and the current is slow, over time, the pan can become a hanging dam: a dense, heavy piece of ice with high ridges and a low centre.

Ice Circle





[edit on 29-12-2009 by flymetothemoon]